Portable roof for open-hearth furnaces



April 1951 J. MCDONALD 2,550,078

PORTABLE ROOF FOR OPEN-HEARTH FURNACES Filed Aug. 27, 1947 INVENTORZ v5% /7-- Jam 4 Mam am,

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Patented Apr. 24, 1 951 PORTABLE ROOF FOR OPEN-HEARTH FURNACES Jack A.McDonald, Duluth, Minn.

Application Augustv 27, 1947, Serial No. 770,780

3 Claims.

This invention relates to open hearth furnace roofs and particularly toroofs formed as replaceable sectional units.

An object of the invention is to provide furnace roof structures formedas individually replaceable, sectional units of improved design, whereinthe arched brickwork is suspended from frames removably supporteddirectly on the buckstays.

improved roof structures as set forth wherein the framework remains apart of the furnace after installation of the roof and may carry otherfurnace elements, such as a door cable sheave or coolant pipes.

A further object of the invention is to provide improved roof structuresreplaceable in sections as pre-constructed units, but accessible forminor repairs without replacement of an entire section.

In accomplishing these and other objects of the present invention, Ihave provided improved structural details, a preferred form of which isshown in the accompanying drawing, wherein:

Figure l is an end elevational view of an open hearth furnace havingroof structure embodying features of the present invention, a wall ofthe furnace being omitted;

Figure 2 is a top plan view of a single roof unit constructed as shownin Figure 1; and

Figure 3 is a side elevational view of the roof unit.

Referring more in detail to the drawing:

In Figure 1 there is shown an open hearth furnace that includes sidewalls l and H, a floor I2, buckstays l3 and I4 and a pre-constructedroof unit l5, of which there are several across the length of thefurnace. The furnace also includes the usual end walls, burners, doorsand other conventional elements, which per se are not involved in thepresent invention and are omitted for the sake of clarity.

In accordance with the present invention, roof unit I5 comprises aframework l6, preferably of steel, from which an arched roof l! issuspended. Framework 16 includes uprights l8 and I9 spaced to registerwith buckstays I3 and M. The lower ends of said uprights preferably aretapered as shown at 20 to interfit with notches 2| in the upper ends ofsaid buckstays. The weight of the roof unit is thereby carried directlyby the buckstays. The framework also includes upper horizontal end andside beams 22 and 23, respectively, a central beam 24 and diagonalbraces 25. The various members are affixed together, as by welding, toform rigid framework open at the bottom.

A further object of the invention is to provide 9 2 A pair oflongitudinally extending skewbacks 26 and 21 are fixed to uprights l8and I9 and their inwardly directed faces are ribbed as shown inFigure 1. Skew bricks 28 and 29, having faces shaped to conform with theribbed faces of said skewbacks, are fitted thereagainst. Bricks 30 toform arched roof I! are placed in an arc between said skewbrioks, beinglaid on a suitable arched form and wired in place. A clamp 3| isprovided for holding the arch bricks from shifting endwise. Wood braces32 may be provided to hold the arch bricks firmly in place while thepre-constructed unit is lifted to the furnace top.

A lifting eye 33v is secured to central beam 24 and is adapted to beengaged by a crane hook 34 for lifting and placing the roof unit. Asheave 35 may be mounted by suitable bearings on the framework forcarrying a door cable. A coolant pipe 36 may also be carried by theframework, Figures 2 and 3.

According to the present invention, an open hearth roof is made up ofseveral units constructed as described and placed end to end. When aroof section is damaged to the extent that replacement is necessary, theold section is removed and a new section lifted in place by suitablemechanical handling means that engage lifting eye 33. The form on whichbricks 3B are laid either can be removed readily or left in place andburned 0n operation of the furnace. Framework 13 remains as a permanentpart of the furnace structure. On furnace operation the brickworkbecomes fused together and is supported by suspension from theframework.

It is seen that one or more roof sections can readily be replacedindividually with a minimum of interruption of furnace operation. Alsothe brickwork in the roof is accessible for minor repairs that do notnecessitate replacement of an entire section.

While I have shown and described only a single embodiment of the presentinvention, it is apparent that modifications may arise. Therefore I donot wish to be limited by the disclosure set forth, but only by thescope of the appended claims.

I claim:

1. In a furnace having walls and upright buckstays, a roof structurecomprising a plurality of sectional units arranged end to end across thelength of the furnace, said units each including framework havinguprights, end and side beams and diagonal braces, said uprightsremovably resting on said buckstays in vertical alignment therewith forsupporting the unit directly on the buckstays, interfitting means on thelower ends of said uprights and on the upper ends of said buckstays forretaining them in vertical alignment, a pair of skewbacks, one of whichbears against the uprights on each side of said framework, skew bricksfitting against said skewbacks, and arched brickwork extending acrossthe sectional unit and bearing against said skew bricks, the units beingindividually removable and replaceable.

2. In a furnace having walls and upright buck-.

stays, a roof structure comprising a plurality of sectional unitsarranged end 'to end across the length of the furnace, said units eachincluding a rigid framework having uprights at each side spacedsimilarly to the furnace buckstays, end

. buckstays, skewbacks extending along the sides of the framework insidesaid uprights and having ribbed faces directed inwardly, skew bricks andside frame members fixed to the upper portions of said uprights, anddiagonal braces fixed to said end and side frame members and said uprights, said uprights removably resting on said buckstays in verticalalignment therewith and forming extensions of the buckstays forsupporting the unit directly on the buckstays, interfitting means on thelower ends of said uprights and on the upper ends of said buckstays forretaining them in vertical alignment, a pair of skewbacks, one of whichbears against the lower portions of the uprights on each side of saidframework above said interfitting means, skew bricks fitting againstsaid skewbacks, and arched brickwork extending across the sectional unitand bearing against said skew bricks, the units being individuallyremovable and replaceable.

3. In an open hearth furnace having walls and secured against saidskewbacks and having faces that conform with said ribbed faces, andarched brickwork between said skew bricks, being there- 'by supported bysuspension from said framework, the units being individually removableand replaceable.

:IACK A. MCDONALD.

' REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 7 Date Number Name Re. 15,977 Kanagy Jan. 6, 1925534,252 Bott Feb. 19, 1895 1,440,446 Cotton Jan. 2, 1923 1,656,963Stevens Jan. 24, 1928 1,677,002 Olson July 10, 1928 1,738,580Himmelright Dec. 10, 1929

